Thruxton 1200r Electrical Problem

I’d suspect a wire shorting out and as it’s when each brake lever is used it looks like it’ll be down the brake light end, check for insulation being worn away on the wires. Change the bulb. Some electrical guru will be along soon to tell you how to run checks on relays or whatever is used

 

unplug the rear light and try. Then the front light.
At least it'll get you closer to an eventual problem.
Check the rear brake cable too!

 

Don’t use the brakes!

 

Hi.Yeah, you have a short in the brake light switch wire. IMHO.

 

Check round the headstock. There was a recall for the thruxton (and a few other models) regarding wires round that area. I not sure but I think the thruxton recall was only valid if you have the cafe racer faring installed.

 

I had a split in a wire you could not see till it was bent, a tiny little 1mm cut, right next to the bracket. I used about 5 fuses trying to find it.

 

To save on fuses, remove the blown fuse and put a test lamp (small 2watt bulb) across the fuse terminals. The bulb will illuminate when the short happens. You can them move the wire about to see when the bulb goes out. This will show the area where the short is. Do-not use a headlamp bulb as it will pull too much current.
Not to be used on circuits where ECMs are involved as they will always draw some current for internal memories.

Alfie

 

Cheers, for posting that good advice.

 

Would also recommend that if it is fitted with a twin filament build to check if one element is shorting to the other. Just try a new build and make sure it is fitted the correct way round.

Alfie

 

You could try disconnecting the tail tidy and apply the brakes to see if the short is in the tail tidy or before.

Alfie

 

I have read in a previous post somewhere that a wire was trapped in a tail tidy and was causing fuses to pop.
Can't find it but I certainly remember it.
As @alfie says, worth a go.

 

That was me possibly. The short I mentioned earlier was right up against the tail tidy on the numberplate light wire.

 

I wasn’t making it up then!!!!

 

I would now be checking continuity junction to junction wire by wire. Lever pressed and not.

 

Having disconnected the Tail Tidy connector without success, you can try following the wiring towards the front of the bike and disconnect connectors as you go.
Most of my experience is with cars where we had access to the wiring diagrams which would show you the location of all the connectors. With cars being a bit longer we used a process called 'the Half Split' approach where you would pick a connector half way between the source and the consumer. Work out what voltage you would expect to see. If less than you expect, move towards the source. If more than you expect, move towards the consumer.

Alfie